The present invention relates to diagnostic apparatus and method for use in determining the proper alignment of one or more laser beams onto a fiber optics interface.
In the prior art, imaging systems are known which focus one or more laser beams onto a fiber optics interface which may have diameters of 500-1000 microns, or even less. If the focused or imaged laser beams are not properly aligned or focused onto the fiber optics interface, a resulting problem is that the tip of the fiber optics interface can be burned. The fiber optics interface in some cases includes the use of plastic clad fibers which are susceptible to burning due to laser energy being absorbed into the plastic material if the laser beam is misaligned. For high energy applications, glass clad fibers are typically used which are more resistant to laser damage problems. However, improper alignment will result in an energy loss due to some light which will never enter into the fiber. It is therefore important that the focused laser beams be aligned properly with the fiber optics interface.
Typical approaches to determining proper alignment of laser beams onto a fiber are to observe the alignment from the side or to insert a beam splitting device in front of the fiber to allow an image of the fiber face to be directed onto a camera. A problem with monitoring from the side of the interface is that the observation is blurred and does not form a good quality image due to the tilted object (with reference to the camera). A problem with using a beam splitting device is that energy is wasted which reflects off the front face of the beam splitter.